A method for detecting the wear of a tyre by means of a processing device is known from FR 2 816 887.
When the tyre is worn beyond a predetermined radial wear threshold, sonic wear gauges emit a characteristic noise of characteristic frequency. This characteristic frequency is dependent especially on the speed of the vehicle, the geometry of installation of the sonic wear gauges and their number.
Knowing the characteristic frequency of the acoustic signal, the acoustic signal is then filtered in the vicinity of the characteristic frequency so as to extract therefrom a gauge signal. Next, a confidence index relating to the gauge signal is calculated. If the index is greater than a predetermined threshold, it is known that the predetermined radial wear threshold has been overstepped.
However, in order to implement this method, it is necessary to know and to store certain parameters of the tyre and of the sonic wear gauges, especially the speed of the vehicle, the geometry of installation of the sonic wear gauges and their number.
It is therefore necessary to have a memory unit into which these parameters are entered and in which they are stored.
In the case of the speed, it is necessary to have a unit for measuring the speed. This unit is linked to the processing device thereby giving rise to an additional cost during the fitting of the device.
Furthermore, when the tyre is changed, the parameters of the latter, especially the geometry of installation of the sonic wear gauges and their number, may change. This then entails modifying the parameters in the memory unit.